(;
AB[rq][rp][qq][pq][oq][or][ps]
AW[rs][os][ns][nr][ro][nq][po][op][pn][rn]
C[Black plays.  What is the best result?]
(;
B[qs]
C[Fails.];
W[qr];B[pr];W[rr];B[sp];W[sr]
C[Black dies.]
)
    (;
    B[sr]
    C[Fails.];
    W[qr];B[pr];W[sp]
    C[Black dies.]
    )
    (;
    B[sp]
    C[Correct.]
    (;
    W[pr]
    C[White can try for the kill with a throw-in that reduces eye-space, but ...];
    B[qr]
    (;
    W[qs];B[pr];W[sr];B[rr]
    C[... but Black lives with territory.]
    (;
    W[so];B[sq]
    C[With 2 outside liberties, Black lives.]
    )
        (;
        W[ss]
        C[Making the bent four now is a wasted move.  Black lives in sente.];
        W[so]
        C[For example ...];
        B[sq];W[rs];B[ss];W[sr];B[qs]
        C[Black lives with territory.]
        )
    )
        (;
        W[sr]
        C[No better.];
        B[qs]
        C[Black lives with territory.]
        )
    )
        (;
        W[sr]
        C[White can also try to create an eye inside, but ...];
        B[rr];W[qs];B[pr]
        C[Black still lives.];
        W[so]
        C[At least White has the possibility of a seki.  But if White doesn't reduce an outside liberty here, later Black can live with territory.]
        )
    )
)

